This is one of eight pinned sticky threads at the top of the Food Safety forum that I refer people to read because it's probably the most asked question and if they read this original post it clears everything up fast and the majority 90%+ needs to keep cooking. Even the Botulism Neurotoxin is a protein so it can be denatured at like 176 for 20 minutes or 185 for five minutes when most questions are about pork butts and briskets going to 203. Sometimes people join SMF just to ask this question and never come back to SMF so putting up the link to find this thread to read the first post saves a lot of explaining. Most regular members are familiar with the Ambient high/low alerts just not a newbie that hasn't gotten a digital therm yet. So I refer a pinned link and say also read the other seven at the top of this forum because they will never be obsolete and go away.I see lots of posts in the form of 'My smoker/oven/grill died, and the meat got cold. Is it safe to eat?'
If you do long, unattended, cooks (i.e., you went to bed), buy yourself a thermometer that has a channel with maximum AND minimum temperature settings, sometimes called a smoker, ambient, or cook chamber thermometer. You can set the alarms outside of your normal cooking range, like 200degF (in case the smoker dies) and 375degF (a grease fire), so you only get notified when something goes wrong. There's no reason to risk your health or ruin a meal when there are solutions available.
I won't suggest any brands, although make sure it also warns you when the transmitter battery goes dead.